Some questions about fetch core data - ios

Question

I'm a new guy with iOS, I made an APP and used Core Data.I could save data in Entity,but I can't fetch it.It's worry grammar or other reason.
I want to fetch data and show in TableViewCell
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:SectionsTableIdentifier];
NSFetchRequest *request = [[NSFetchRequest alloc]initWithEntityName:#"Entity"];
NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:#"showName" ascending:NO];
request.sortDescriptors = #[sort];
request.fetchLimit = 100;
request.fetchOffset= 0;
NSError *error = nil;
NSArray *array = [self.context executeFetchRequest:request error:&error];
NSMutableDictionary *names = [NSMutableDictionary dictionaryWithCapacity:1];
if(!error){
for (Entity *emp in array ) {
NSLog(#"output：%#",emp.showName);
names =[NSMutableDictionary dictionaryWithObjectsAndKeys:emp.showName, nil];
self.keys =[[self.names allKeys]sortedArrayUsingSelector:#selector(compare:)];
}
}
else{
NSLog(#"%#",error);
}
}
and this is my code with save data
-(IBAction)addButton:(id)sender{
AppDelegate *appDelegate = [UIApplication sharedApplication].delegate;
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSInteger seasonRow = [self.dataPicker selectedRowInComponent:kSeason];
NSInteger episodeRow = [self.dataPicker selectedRowInComponent:kEpisode];
Entity * tvShow1 =[NSEntityDescription insertNewObjectForEntityForName:#"Entity"
inManagedObjectContext:context];
NSError * error = nil;
NSString *name = self.nameField.text;
NSString *introduction = self.introductionField.text;
NSString *dateSeason = self.seasonNumber[seasonRow];
NSString *dateEposide = self.episodeNumber[episodeRow];
NSString *date;
date = [dateSeason stringByAppendingString:dateEposide];
tvShow1.showName =name;
tvShow1.showIntroduction = introduction;
tvShow1.showLastedData = date;
if (!error) {
NSLog(#"保存成功");
NSString *message = [[NSString alloc]initWithFormat:#"你的新剧：%#已经成功添加",name];
UIAlertController *alert=
[UIAlertController alertControllerWithTitle:#"恭喜，添加成功"
message:message
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *action = [UIAlertAction actionWithTitle:#"好嘞！"
style:UIAlertActionStyleDefault
handler:nil];
[alert addAction:action];
[self presentViewController:alert animated:YES completion:nil];
[self.contenxt save:&error];
}
[appDelegate saveContext];
}
Thank you very much!